title: Influence of 2% chlorhexidine gel on calcium hydroxide ionic dissociation and its ability of reducing endotoxin.
abstract: OBJECTIVE
  The aim of this study was to evaluate the influence of 2% chlorhexidine gel (CHX) on pH, calcium release, and Ca(OH)(2) capability of reducing endotoxin.
  
  
  METHODS
  Calcium release was verified by atomic-absorbance spectrophotometry, and pH was measured with a pHmeter. For endotoxin quantification, extracted human teeth previously contaminated with standard endotoxin were filled with: group I, Ca(OH)(2) + saline solution; group II, Ca(OH)(2) + CHX; and group III, CHX for 14 days. The remaining endotoxin was quantified by using chromogenic quantitative test. Statistical analysis was performed with analysis of variance and Tukey post hoc test (P < .05).
  
  
  RESULTS
  Group II released more calcium than group I (P < .05) after 15 days. Groups I and II showed alkaline pH in all periods, and group I showed higher pH values than group II (P < .05) after 30 days. Groups II and III showed significantly more decreased endotoxin than group I.
  
  
  CONCLUSIONS
  CHX did not interfere with the chemical properties of Ca(OH)(2), in fact even improving its properties of reducing the endotoxin content in root canals in vitro.
authors.affiliation: Endodontic Division, Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
authors.forename: Fernanda Graziela Correa
authors.initials: FG
authors.lastname: Signoretti
authors.forename: Brenda Paula Figueiredo de Almeida
authors.initials: BP
authors.lastname: Gomes
authors.forename: Francisco
authors.initials: F
authors.lastname: Montagner
authors.forename: Fernanda
authors.initials: F
authors.lastname: Barrichello Tosello
authors.forename: Rogério Castilho
authors.initials: RC
authors.lastname: Jacinto
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002118:Calcium / Q000032:analysis; D002126:Calcium Hydroxide / Q000737:chemistry*; D002710:Chlorhexidine / Q000494:pharmacology*; D004731:Endotoxins / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000032:analysis; D008033:Limulus Test; D012388:Root Canal Irrigants / Q000737:chemistry*; D018709:Statistics, Nonparametric
chemical_list: D000891:Anti-Infective Agents, Local; D004731:Endotoxins; D006878:Hydroxides; D012388:Root Canal Irrigants; C044101:endotoxin, Escherichia coli; C031356:hydroxide ion; D002126:Calcium Hydroxide; D002710:Chlorhexidine; D002118:Calcium